Sender Score: Email Blocklist Removal Guide
Harness the power of the Sender Score Reputation Network to monitor email trustworthiness and discover proven strategies for improving your sender reputation today.
Blocklists & Spam Monitoring
Backscatterer Removal: How to Delist Your Mail Server from ips.backscatterer.org
Lists IPs that generate backscatter: misdirected delivery failure notifications (NDRs) sent to forged sender addresses. Operated by the same team as UCEPROTECT.
BLOCKLIST.DE: Email Blocklist Removal Guide
Automated blocklist fed by fail2ban reports from a network of participating servers. Lists IPs involved in brute-force attacks, SSH scans, and other network intrusion attempts in addition to email ...
HIL Blacklist: Email Blocklist Removal Guide
Formerly a sender certification and reputation list from Habeas (acquired by Return Path). Discontinued when Return Path moved to different certification models.
DroneBL: Email Blocklist Removal Guide
Lists IPs operating as botnet drones, open proxies, and compromised hosts. Oriented toward IRC network abuse but used in some mail filter configurations.
RATS Blacklists: Email Blocklist Removal Guide
Family of IP blocklists covering dynamic IPs (RATS-Dyna), confirmed spam sources (RATS-Spam), and IPs with no PTR record (RATS-NoPtr). Used in SpamAssassin and Postfix configurations.
IMP Blacklist: Email Blocklist Removal Guide
Swiss academic network blocklist covering spam sources and worm-infected hosts. Used within the Swiss and European academic mail infrastructure.
NETHER Blacklists: Email Blocklist Removal Guide
Formerly listed open relays (RELAYS zone) and uncertain mail sources (UNSURE zone). Has not been actively maintained since the mid-2010s. Still queried by some legacy SpamAssassin configurations.
DAN TOR: Email Blocklist Removal Guide
Lists known Tor exit nodes. Not a spam blocklist but used by some mail servers to flag or reject mail from anonymous Tor network infrastructure.
SPFBL DNSBL: Email Blocklist Removal Guide
Brazilian-origin blocklist combining SPF-based sender validation with traditional DNSBL listing. Lists IPs that fail SPF checks or are associated with spam sources in the SPFBL network.
Suomispam Reputation: Email Blocklist Removal Guide
Finnish blocklist covering spam sources identified via local trap networks. Primarily used by Finnish ISPs and regional mail infrastructure.
Email Blocklist Directory: 47 DNSBLs Explained
Reference catalog of 47 DNS-based email blocklists. Each entry covers what the list targets, how it affects SMTP delivery, and how to request removal.
